textproduct: Quad Cities

KEY MESSAGES

- An Excessive Heat Warning is now in effect for the I-80 corridor on south through Friday. Heat indices look to be 100-105 but the upgrade to the warning is due to the longevity of the heat. A Heat Advisory remains in effect through Thursday north of I-80.

- The Storm Prediction Center has a Marginal, level 1 out of 5, Risk for severe storms for Thursday and Friday. The primary risk is damaging winds with hail a secondary risk.

- There is a near daily risk of showers and storms, mainly along and north of I-80. While there is a risk of rain, there will be plenty of dry hours.

SHORT TERM /THROUGH TONIGHT/

Issued at 203 AM CDT Wed Sep 2 2026

CHANGES...

The heat advisory for the I-80 corridor on south has been extended through Friday and upgraded to a warning. The warning upgrade is due to the longevity of heat indices of 100+ for four consecutive days.

The heat headlines north of I-80 may get extended as well. However, there is higher uncertainty north of I-80 given the potential for showers and storms on Friday.

Discussion

Storm complex moving east across southern Minnesota and into Wisconsin with CAMs show precipitation staying mainly north of the area. However, some of the CAMs are trying to push an outflow boundary into the Highway 20 corridor around or just after sunrise. REFS does have a low (20%) probability of this boundary initiating some showers or even a thunderstorm around sunrise. The remainder of the area will remain dry.

Said boundary will then push north out of the area during the day with some convection festering along it. The diurnal convection that develops near the boundary has a 20 percent probability of getting into the Highway 20 corridor during the afternoon and early evening.

The main message is the continued heat and humidity. Another day of triple digit heat indices will be seen for much of the area. A light southerly wind will not bring much relief.

Tonight there may or may not be some isolated convection in the Highway 20 corridor through sunset. Most of the area will remain dry.

After midnight things become a bit more interesting. Another storm complex will develop in the Plains and move east. This complex appears to be a bit further south than the Wednesday complex. If correct then there is a 20-35% chance of some showers/storms potentially reaching as far south as Highway 30 in the pre-dawn hours Thursday.

LONG TERM /THURSDAY THROUGH TUESDAY/

Issued at 235 PM CDT Tue Sep 1 2026

Thursday...Latest ensemble upper ridge placement and thermal gradient projections suggest another hot day of headline worthy heat, but also some upper ridge retrograde may be enough to allow for some convection to spill further southeast and possibly impact portions of the local fcst area especially Thu night into Friday morning. But that being said, some of the longer range CAMs such as the latest RRFS suggest bulk of the convection this day to occur to the north and east of the CWA. If organized storms/ clusters do manage to make it down this way, severe weather and damaging winds would be probable.

Friday...Depending on the potential for more storms down our way or at least convective debris and storm outflow, like the previous shift mentioned, this day may need an eventual heat headline. And if it does, the several days of high heat in a row rule may foster the need for an upgrade to an Extreme Heat Warning.

A look ahead to the upcoming weekend: Saturday could be a continuation of the hot humid weather and possible need of heat headlines, depending on storms and cloud debris. But then the heat may decrease by Sunday if we can get a backdoor style cool front from ridging acrs the western GRT LKS. This may be temporary with ensemble signs in the medium range runs of the heat dome trying to reestablish from the west and back acrs the region by mid next week.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 555 AM CDT Wed Sep 2 2026

Expect a continuation of prevailing VFR today into tonight. Light winds early this morning will increase to 10-15 kts from the SSW for the remainder of the day. An isolated shower or storm is possible this afternoon through tonight (<20%); however, potential is too low to include in the TAFs with this update.

CLIMATE

Issued at 222 PM CDT Sun Aug 30 2026

Record Warm Low Temperatures:

September 2: KDBQ: 74/2011 KMLI: 77/1913

September 3: KDBQ: 73/1939 KMLI: 76/1939

September 4: KDBQ: 71/1912 KMLI: 74/2018

September 5: KDBQ: 76/1881 KMLI: 76/1925

DVN WATCHES/WARNINGS/ADVISORIES

IA...Heat Advisory until 7 PM CDT Thursday for IAZ040>042-051>054- 066. Extreme Heat Warning until 7 PM CDT Friday for IAZ063>065-067- 068-076>078-087>089-098-099. IL...Heat Advisory until 7 PM CDT Thursday for ILZ001-002-007-009. Extreme Heat Warning until 7 PM CDT Friday for ILZ015>018- 024>026-034-035. MO...Extreme Heat Warning until 7 PM CDT Friday for MOZ009-010.